Cameron-Whytock Heather, Divall Hannah, Lewis Martin, Apps Charlotte
School of Veterinary Medicine, University of Central Lancashire, Preston PR1 2HE, UK; School of Animal Rural and Environmental Science, Nottingham Trent University, Brackenhurst Campus, Southwell NG25 0QF, UK.
School of Science and Technology, Nottingham Trent University, Clifton Campus, Clifton NG11 8NS, UK.
J Biomech. 2025 Jun;186:112728. doi: 10.1016/j.jbiomech.2025.112728. Epub 2025 Apr 26.
The study hypothesised that a markerless motion capture system can provide kinematic data comparable to a traditional marker-based system for riders mounted on a horse. The objective was to assess the markerless system's accuracy by directly comparing joint and segment angle measurements taken during walking and trotting with those obtained from a marker-based system. Ten healthy adult participants performed five dynamic trials during walking and trotting. A twelve-camera marker-based system and eight-camera 2D video-based system were synchronised. Three-dimensional hip, knee, shoulder and elbow joint angles, and the global trunk and pelvis angle were computed for comparison between the two systems. To assess the error between systems, the root mean square difference (RMSD) was averaged across each gait cycle and statistical parametric mapping (SPM) paired t-tests were applied. The sagittal trunk angle had the lowest RMSD of 2.0° and elbow rotation had the highest RMSD of 19°, with the same values for walking and trotting. SPM indicated increased hip flexion (0-100 %, p < 0.001) and elbow flexion (24-47 %, p = 0.03; 63-100 %, p < 0.001) in the walking gait cycle for the markerless system. A lack of joint range of motion and obscured medial limbs during walking whilst mounted on horses may cause increased offsets for markerless data in equestrian riders. No significant differences were found for the transverse plane, yet there tended to be increased RMSD. This lack of consistency suggests results from the transverse plane in equestrian riders should be interpreted with caution. Study findings indicate that markerless technology has the potential to be a suitable alternative to marker-based systems for assessment of equestrian riders, dependent on the segment/joint angle of interest and the level of acceptable error. These results indicate that markerless systems can effectively be utilised for rider biofeedback, though their application may be limited for specific joint analyses.
该研究假设，对于骑在马背上的骑手而言，无标记运动捕捉系统能够提供与传统基于标记的系统相当的运动学数据。目的是通过直接比较行走和小跑过程中无标记系统与基于标记的系统所获取的关节和节段角度测量值，来评估无标记系统的准确性。十名健康成年参与者在行走和小跑过程中进行了五次动态试验。一个基于十二个摄像头的标记系统和一个基于八个摄像头的二维视频系统进行了同步。计算了三维髋、膝、肩和肘关节角度，以及整体躯干和骨盆角度，以便在两个系统之间进行比较。为了评估系统之间的误差，对每个步态周期的均方根差（RMSD）进行平均，并应用统计参数映射（SPM）配对t检验。矢状面躯干角度的RMSD最低，为2.0°，肘关节旋转的RMSD最高，为19°，行走和小跑时的值相同。SPM表明，无标记系统在行走步态周期中髋部屈曲增加（0 - 100%，p < 0.001），肘部屈曲增加（24 - 47%，p = 0.03；63 - 100%，p < 0.001）。骑在马上行走时关节活动范围不足以及内侧肢体遮挡，可能会导致无标记数据在马术骑手身上的偏移增加。在横断面未发现显著差异，但RMSD往往有所增加。这种缺乏一致性表明，马术骑手横断面的结果应谨慎解读。研究结果表明，无标记技术有可能成为评估马术骑手时基于标记系统的合适替代方案，这取决于感兴趣的节段/关节角度以及可接受误差水平。这些结果表明，无标记系统可有效地用于骑手生物反馈，尽管其应用可能在特定关节分析方面受到限制。
